SimpleDateFormat is not thread safe

[Daniel Zoller]

... but we use it as constant.

Please replace all occurrences with joda time, except the ones in -model, -rest-client, -rest-common. In these modules we can't use the joda time dependency so only remove the constant of the simpledateformat

[Robert Jäschke]

Oha! I thought I looked that up. Damn implementation! :-(

[Thomas Niebler]

Many references are still in the code. Not yet fixed.

[Former user]

• All occurrences of SimpleDateFormat outside of the aforementioned modules have been replaced with the joda time equivalent
• Occurrences in those modules are no longer constant

[Lena Hettinger]

Closing branch: sdf1732 Fixing #1732

→ <<cset fe19daeea5d9>>